International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

The paper studies the process of restoration of worn-out parts of agricultural machinery under submerged arc welding, produces definable and determining similarity criteria characterizing the process and discloses their physical entity. The methodology is developed and the criterion equation is received for determining and optimizing the hardness of metal coatings obtained, which is a scientific basis for conducting targeted experiments. An outfit is made for surfacing ploughshares submerged, that allows changing the basic factors without stepwise method. Experimental studies are conducted, as a result of which an analytic form of criteria equation is produced and optimum modes of the recovery of details under gumboil arc welding are established mined in Georgia.

Calculating and increasing the reliability indicators of machines is an important problem as they won’t be competitive in the world market without this high indicator. Currently, many scientists have developed scientific foundations for calculating the reliability of machines, installations, instruments and devices in radio electronics, aviation, space, mechanical engineering and other industries, but such research is not acceptable for agricultural machines that operate in special soil-climatic and dynamic conditions. Their working bodies are constantly subject to alternating dynamic loads, abrasive particles in the cultivated soil, exposure and inclination of the relief, high humidity, high radiation, etc. All these factors cause intensive wear of their working bodies and therefore, such machines are subject to special requirements for reliability. In addition, agricultural machines must have high reliability due to the fact that harvesting is carried out in a short time and failures of such machines lead to significant losses of agricultural products. We have developed theoretical principles and methods for calculating the reliability of agricultural machines, taking into account the specifics of their designs and operating conditions. For this purpose, modern methods of probabilistic-statistical modeling, queuing theory, similarity and dimensions were used. A methodology for calculating reliability was also developed taking into account the structural and logical diagrams of machines and such diagrams of specific machines were drawn up.

The hardness of iron-nickel coatings during the restoration of worn parts is an important factor determining the service life of machines. This mechanical property depends on many factors, the simultaneous influence of which cannot be taken into account in conventional experiments. Therefore, we have made an attempt to simultaneously use the complex methods of similarity theories and planning multifactorial experiments to study the hardness of iron-nickel coatings. The composition of the electrolyte was obtained by us with a copyright certificate for the invention No. 700568, Moscow, 1989, Katsitadze J.V.,. Kikabidze D . N . “Electrolyte for obtaining plated iron-nickel alloy”. This approach to the issue allows taking into account the simultaneous influence of a large number of factors on the optimization parameter, obtaining reliable and reasonable results in the form of regression equations, optimizing the process of restoring machine parts with an iron-nickel electrolytic alloy and generalizing the results obtained.
In the article, the influence of technological similarity criteria on the hardness of iron-nickel coatings is explored, the response function is obtained depending on the dimensionless similarity criteria and the corresponding mathematical model is used to carry out targeted experiments according to the Box-Benkin plan. As a result of mathematical processing of the obtained data, an adequate regression equation was derived, according to which the optimal electrolyte composition and electrolysis conditions have been

Adjara, with its diverse natural conditions, relief and soil and climatic features, is one of the distinctive regions of Georgia, dominated by mountainous terrain, steep slopes and small areas. Accordingly, the complex mechanization of agricultural processes by mobile agricultural machinery is inappropriate and therefore small-sized agricultural machinery is used. This technique works in difficult soil-climatic and dynamic conditions, it is constantly affected by significant dynamic forces, high humidity, abrasive particles in the environment, mountainous terrain and others. All these factors cause intensive wear and decrease in the reliability of the working bodies of machines. It should be noted that single and complex indicators of the operational reliability of small-scale mechanization equipment operating in the mountainous conditions of Adjara have not been studied and their establishment will contribute to the rational organization of technical service of small-scale mechanization machines.
The reliability indicators of motoblocks and motor cultivators, such as the probability of failure-free operation, time between failures, the failure rate parameter, the average resource, the coefficients of technical use and readiness, are considered, adequate probabilisticstatistical mathematical models are obtained, the least reliable nodes, types of failures are identified, and a set of measures is outlined to improve reliability

The article examines the single and complex indicators of the operational reliability of agricultural machinery (tractors and combines) operating in the special soil-climatic and dynamic conditions of Georgia, highlights the least reliable units and parts that require constructive improvement.
As a result of research, according to the methodology of probabilistic and statistical modeling developed by us, integral and differential distribution functions of reliability indicators were obtained, their general characteristics were determined, as well as mathematical models and the values of reliability indicators were determined taking into account the distribution law. The adequacy of the probabilistic-statistical models was tested using the Pearson and Kolmogorov goodness-of-fit tests.
As a result of theoretical and experimental studies, characteristic malfunctions and failures of the main units of foreign ag ricultural equipment operating in Georgia have been established, and constructive and technological measures to improve reliability have been developed.

The article proposes a fundamentally new design of a resource-saving, anti-erosion unit that significantly improves the quality of soil tillage in cultivating agricultural crops, improves the productivity of the plow, significantly eliminates soil erosion and reduces the fuel consumption of the tractor by reducing the traction resistance.
The construction of the unit and the principle of its operation are described in detail. It can be successfully used both in plain and in mountainous terrain.
Characteristic similarity criteria and a criterion equation for studying the traction force of the proposed unit are obtained and their physical meaning is revealed

The article explored the operational reliability of agricultural machinery of low mechanization operating in the mountain conditions of Ajara, carried out the classification of machine parts on the basis of their structural and technological homogeneity and specific working conditions, highlighted the least reliable components and parts, developed a theoretical basis for calculating the reliability in contrast to mobile machines , the corresponding structural and logical schemes were drawn up.
As a result of statistical studies, integral and differential distribution functions of reliability indicators have been obtained, their general characteristics have been determined and the values of single and complex reliability indicators have been determined, resource-saving technology has been developed to increase the reliability and resource of mini-technology. technology for the region of Adjara, as well as its parameters and rational about service-organization of the pilot plant.